Two-stage hypersonic vehicle featuring advanced swirl combustion

Abstract

The present invention is directed toward a two-stage hypersonic vehicle, comprising a first-stage vehicle and a second stage vehicle. The first-stage vehicle includes a combined-cycle engine and a swirl generator for propelling the first-stage vehicle and the second-stage vehicle to a threshold velocity, which in one embodiment is about Mach 6. In one embodiment, the first-stage combined-cycle engine integrates a swirl generator into a gas turbine engine, providing a highly compact afterburner and a ramjet engine within the gas turbine engine. One benefit of the integrated swirl generator is the ability to significantly reduce overall first-stage gas turbine and afterburner-ramjet size and weight, while retaining high performance. The second-stage vehicle is detachably secured to the first-stage vehicle and includes a hypersonic engine. In various embodiments, the hypersonic engine may comprise one of the following engine configurations: scramjet, rocket, or scramjet/rocket depending on the mission profile and requirements.

1 . A two-stage hypersonic vehicle comprising:
 a first-stage vehicle for propelling the two-stage vehicle to a threshold velocity, the first-stage vehicle including:
 a combined-cycle turbo-ramjet engine for producing thrust with combustion processes; and 
 a swirl generator for mixing combustion constituents in a combustion process of the combined-cycle engine; and 
   a second-stage vehicle detachably secured to the first-stage vehicle, the second-stage vehicle including a hypersonic engine for operating at the threshold velocity such that the second-stage vehicle is operable when detached from the first-stage vehicle.   
   
   
       2 . The two-stage vehicle of  claim 1  wherein the hypersonic engine comprises a scramjet engine. 
   
   
       3 . The two-stage vehicle of  claim 2  wherein the threshold speed comprises a speed viable for scramjet operation. 
   
   
       4 . The two-stage vehicle of  claim 2  wherein the threshold speed is approximately Mach 5 to approximately Mach 6. 
   
   
       5 . The two-stage vehicle of  claim 2  wherein the scramjet operates utilizing airflow having supersonic and above velocities as is produced by the propulsion of the first-stage vehicle by the combined-cycle turbo-ramjet engine. 
   
   
       6 . The two-stage vehicle of  claim 2  wherein the scramjet engine comprises:
 an inlet for compressing a supersonic air flow;   a fuel injector for injecting a supply of a fuel into the supersonic air flow;   an expanding combustor for combusting the fuel in the supersonic air flow and accelerating the air flow; and   an exhaust nozzle for further accelerating the supersonic air flow to produce thrust as it exits the air-breathing hypersonic engine.   
   
   
       7 . The two-stage vehicle of  claim 2  wherein the second-stage vehicle further comprises a rocket-engine. 
   
   
       8 . The two-stage vehicle of  claim 1  wherein the hypersonic engine comprises a rocket-engine. 
   
   
       9 . The two-stage vehicle of  claim 1  wherein the hypersonic engine includes a combined ramjet and scramjet engine. 
   
   
       10 . The two-stage vehicle of  claim 1  wherein the combined-cycle turbo-ramjet engine comprises:
 a gas turbine engine for providing initial thrusting of the two-stage vehicle and accelerating the two-stage vehicle to supersonic ramjet takeover speed; and   a ramjet engine for accelerating the two-stage vehicle to hypersonic threshold speed.   
   
   
       11 . The two-stage vehicle of  claim 10  wherein the swirl generator operates as an afterburner for the gas turbine engine. 
   
   
       12 . The two-stage vehicle of  claim 10  wherein the swirl generator operates as a ramjet engine. 
   
   
       13 . The two-stage vehicle of  claim 1  wherein the swirl generator comprises:
 a centerbody for positioning in a flow stream of a first combustion constituent of the combined-cycle engine;   a vane pack for introducing a turbulent three-dimensional flowfield having a central recirculation zone downstream of the vane pack in the flow stream of the first combustion constituent;   a set of fuel injectors selected from the group consisting of wall-type, centerbody and bluffbody injectors, the set of fuel injectors for introducing a second combustion constituent into the three-dimensional turbulent flowfield;   a dump-step for anchoring an outer recirculation zone of the flow stream of the first combustion constituent and for anchoring a turbulent mixing-combusting shear layer of the outer recirculation zone of the combustion process;   an ignition system for initiating and sustaining a combustion process between the first combustion constituent and the second combustion constituent; and   a bluffbody for providing improved mixing of the combustion constituents, anchoring the central recirculation zone and for providing a flame anchor for the combustion process.   
   
   
       14 . A propulsion system for a two-stage vehicle, the propulsion system comprising:
 a first-stage propulsion system for a first-stage vehicle, the first-stage propulsion system comprising:
 a combined-cycle engine for providing initial thrusting of the two-stage vehicle; and 
 a swirl generator for mixing combustion constituents in a combustion process of the first-stage propulsion system such that the two-stage vehicle is accelerated to a scramjet threshold speed; 
   a second-stage propulsion system for a second-stage vehicle detachably affixed to the first-stage vehicle, the second-stage propulsion system comprising a hypersonic engine for operating at the scramjet threshold speed and beyond.   
   
   
       15 . The propulsion system of  claim 14  wherein the hypersonic engine comprises a scramjet engine. 
   
   
       16 . The propulsion system of  claim 15  wherein the scramjet threshold speed comprises a speed viable for hypersonic operation. 
   
   
       17 . The propulsion system of  claim 15  wherein the scramjet threshold speed is approximately Mach 5 to approximately Mach 6. 
   
   
       18 . The propulsion system of  claim 15  wherein the scramjet operates utilizing airflow having supersonic and above velocities as is produced by the propulsion of the first-stage vehicle by the combined-cycle engine. 
   
   
       19 . The propulsion system of  claim 14  wherein the combined-cycle engine comprises:
 a gas turbine engine for providing initial thrusting of the two-stage vehicle; and   a ramjet for accelerating the two-stage vehicle to supersonic speeds.   
   
   
       20 . The propulsion system of  claim 19  wherein the swirl generator operates as an afterburner for the gas turbine engine. 
   
   
       21 . The propulsion system of  claim 19  wherein the swirl generator operates as a ramjet engine. 
   
   
       22 . The propulsion system of  claim 19  wherein the first-stage propulsion system comprises a split-flow configuration wherein the combined-cycle engine and the ramjet occupy separate airflow space. 
   
   
       23 . The propulsion system of  claim 19  wherein the first-stage propulsion system comprises a combined-flow configuration wherein the combined-cycle engine and the ramjet share airflow space. 
   
   
       24 . The propulsion system of  claim 19  wherein the first-stage propulsion system includes variable ducting for controlling airflow through the first-stage propulsion system. 
   
   
       25 . A two-stage vehicle comprising:
 a first-stage vehicle powered by a combined-cycle engine having a swirl generator such that the first-stage vehicle achieves a staging Mach number from about Mach 5 to about Mach 6; and   a second-stage vehicle powered by a scramjet engine operable at the staging Mach number, wherein the scramjet engine is characterized by the absence of components necessary for subsonic operation.